Retrievable inferior vena cava filter to prevent pulmonary embolism in patients with fractures and deep venous thrombosis of lower extremities: a single-center experience

Inferior Vena Cava Filters and Complications: A Systematic Review

Inferior vena cava (IVC) filters have been used since the 1960s to treat patients with acute risk of pulmonary embolism (PE) to prevent migration of thrombus by trapping it within the filter. Traditional usage has been in patients with contraindication to anticoagulation that carry a significant mortality risk. In this systematic review, we sought to evaluate complications associated with placement of inferior vena cava filters based on published data from the past 20 years. A search was performed on October 6th, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, using three databases (ProQuest, PubMed and ScienceDirect) for articles published between the dates of February 1, 2002 and October 1, 2022. Results were filtered to include full-text, clinical studies, and randomized trials written in English pertaining to keywords "IVC filter AND complications", "Inferior Vena Cava Filter AND complications", "IVC filter AND thrombosis" and "Inferior Vena Cava Filter AND thrombosis". Articles identified by the three databases were pooled and further screened for relevance based on inclusion and exclusion criteria. Initial search results yielded 33,265 hits from all three databases combined. Screening criteria were applied, with 7721 results remaining. After further manual screening, including removal of duplicate hits, a total of 117 articles were selected for review. While there are no consensus guidelines for best practice, there is compelling evidence that IVC filters can provide significant protection against PE with minimal complications if the treatment window is appropriate. Increase in the variety of filter models has led to broader availability, but skepticism remains about their efficacy and safety, with ongoing controversy surrounding appropriate indications. Further research is needed to establish clear guidelines on appropriate indications for IVC placement and to determine time course of complications versus benefits for indwelling filters.

The application of inferior vena cava filters in orthopaedics and current research advances

Deep vein thrombosis is a common clinical peripheral vascular disease that occurs frequently in orthopaedic patients and may lead to pulmonary embolism (PE) if the thrombus is dislodged. pulmonary embolism can be prevented by placing an inferior vena cava filter (IVCF) to intercept the dislodged thrombus. Thus, IVCFs play an important role in orthopaedics. However, the occurrence of complications after inferior vena cava filter placement, particularly recurrent thromboembolism, makes it necessary to carefully assess the risk-benefit of filter placement. There is no accepted statement as to whether IVCF should be placed in orthopaedic patients. Based on the problems currently displayed in the use of IVCFs, an ideal IVCF is proposed that does not affect the vessel wall and haemodynamics and intercepts thrombi well. The biodegradable filters that currently exist come close to the description of an ideal filter that can reduce the occurrence of various complications. Currently available biodegradable IVCFs consist of various organic polymeric materials. Biodegradable metals have shown good performance in making biodegradable IVCFs. However, among the available experimental studies on degradable filters, there are no experimental studies on filters made of degradable metals. This article reviews the use of IVCFs in orthopaedics, the current status of filters and the progress of research into biodegradable vena cava filters and suggests possible future developments based on the published literature by an electronic search of PubMed and Medline databases for articles related to IVCFs searchable by October 2022 and a manual search for citations to relevant studies.

Evaluation of hemodynamic effects of different inferior vena cava filter heads using computational fluid dynamics

Inferior vena cava (IVC) filters are used to prevent pulmonary embolism in patients with deep vein thrombosis for whom anticoagulation is unresponsive. The head is a necessary structure for an Inferior vena cava filter (IVCF) in clinic use. At present, there are various head configurations for IVCFs. However, the effect of head pattern on the hemodynamics of IVCF is still a matter of unclear. In this study, computational fluid dynamics is used to simulate non-Newtonian blood flows around four IVCFs with different heads inside an IVC model, in which the Denali filter with a solid and hooked head is employed as a prototype, and three virtual variants are reconstructed either with a no-hook head or with a through-hole head for comparison. The simulation results show that the through-hole head can effectively avoid the recirculation region and weaken the blood flow stasis closely downstream the IVCF head. The shape change of the filter head has no significant effect on the blood flow acceleration inside the IVCF cone as well as little influence on the wall shear stress (WSS) distribution on the filter wire surface and IVC wall. The structure pattern of filter head greatly affects the flow resistance of its own. However, the flow drag of filter head only occupies a small proportion of the total resistance of IVCF. Therefore, to reduce the flow resistance of an IVCF should optimize its whole structure.

Incidence and risk factors of preoperative deep vein thrombosis in patients with intertrochanteric fractures: a retrospective study

BACKGROUND

The risk of perioperative complications remains high in patients with intertrochanteric fractures. Immobilization after injury may predispose these patients to deep vein thrombosis (DVT) while waiting for surgery. The aims of this study were to determine the incidence of preoperative DVT in patients with intertrochanteric fractures and identify independent risk factors.

METHODS

This retrospective study included patients with intertrochanteric fractures waiting for surgical interventions at our institution from June 2018 to December 2020. All patients received pharmacologic thromboprophylaxis after admission and ultrasound screening for DVT in both lower limbs before surgery. Demographic, clinical and laboratory data of these patients were collected to perform univariate analysis first. Subsequently, factors with a significant difference in univariate analysis were introduced into the multivariate logistic regression analysis to determine the independent risk factors for preoperative DVT.

RESULTS

A total of 266 patients were enrolled in this study. Seventy-one patients (26.7%) developed DVTs before surgery. The majority of DVTs were distal types (91.5%). There were 40 patients with DVTs only in the affected limb, 7 patients with DVTs only in the unaffected limb, and 24 patients with DVTs in both lower limbs. Advanced age, female, prolonged period from injury to admission, combined cranial trauma, shorter thrombin time, increased level of D-dimer and lower level of albumin proved to be the independent risk factors for preoperative DVT.

CONCLUSIONS

We observed a high incidence of preoperative DVT in patients with intertrochanteric fractures. Identification of patients at high risk may improve the prevention and treatment of preoperative DVT in this population.

Effects of CDT on Hemodynamics and Quality of Life in a Subgroup of Patients with Lower Limb Deep Vein Thrombosis Carel: A Case-Control Study

Objective. To explore the effects of combined catheter-directed thrombolysis (CDT) on hemodynamics and quality of life in a subgroup of patients with lower limb deep vein thrombosis carel by using a case-control study. Methods. Eighty-four patients with deep venous thrombosis (DVT: acute DVT and chronic DVT) of lower extremities treated in our hospital from April 2017 to June 2021 were randomly assigned into the control group ( $n=42$ ) and the research group ( $n=42$ ). The control group only received routine nursing combined with CDT; the research group was treated with cluster nursing l combined with CDT. The clinical efficacy, the difference in limb circumference, hemorheology, hemodynamics, coagulation index and life quality before and after treatment, and the nursing satisfaction scores were calculated. The effects of cluster nursing l combined with CDT on hemodynamics and life quality in patients with DVT of lower extremities were analyzed. Results. The clinical curative effect of the research group was better than that of the control group ( $P<0.05$ ). After intervention, the difference in the thigh and leg perimeter in the research group was reduced, and the difference in the thigh and leg perimeter in the research group was significantly lower than that in the control group ( $P<0.05$ ). After intervention, the whole blood low shear viscosity, plasma viscosity, platelet aggregation rate, and fibrinogen in the research group were lower than those in the control group ( $P<0.05$ ). After intervention, segmental venous volume (SVC), maximum venous blood flow (MVO), and SVC/MVO in the research group were significantly higher than those before intervention, VRT was significantly prolonged, and MVO and venous pressure recovery time (VRT) were significantly higher than those in the control group. After intervention, D-dimer and fibrinogen decreased, prothrombin time and activated partial thromboplastin time increased in the research group, and the improvement of blood coagulation index in the research group was significantly better than that in the control group ( $P<0.05$ ). After intervention, the scores of quality of life in the research group decreased, and the scores of physiological function, psychological function, social function, and health self-cognition in the research group were lower than those in the control group ( $P<0.05$ ). The satisfaction of patients in the research group was significantly higher than that in the control group ( $P<0.05$ ). Conclusion. The application of cluster nursing l combined with CDT can effectively prevent lower limb venous thrombosis after operation and can enhance patients’ hemorheology, hemodynamics, and blood coagulation function and significantly promote their life quality, nursing satisfaction is high, and it is worth popularizing and applying in clinic.